Water-resistant carboxylic acid-polyhydric alcohol resin



Patented Apr. 24, 1928.

UNITED STATES PATENT orrics.

CHARLES n. DOWNS, or cmrrsrn'n, AND LOUIS wnrsmine, or emurwoon, New

messy, assrenozas r rnnnamm'r'r comramz, A coaronsrrou or NEW mn- SEY. I

WATER-RESISTANT CABBOXYI IIC ACID YOLYHYDRIC ALCOHOL RESIN.

No Drawing. Original application filed December 22, 1920, Serial No. 482,408. lJiv'ide'd and this application filed September 7, 1921. Serial No. 498,996. i

This application is a division of our application, Serial No. 432,408, filed December 22, 1920, and is directed to the matter defined by the claims appended hereto and forming a part hereof.

Resinous materials of widely difierent properties have heretofore been made from glycerol by suitable combination thereof with a dibasic aromatic acid alone, a'dibasic aliphatic acid'alone and also with a mixture of varying proportions of both an aromatic dibasic and an aliphatic dibasic acid. See U. s. Patents: 1,082,106, Dec. 23, 1913; 1,- 091,627, Mar. 31, 1914; 1,091,628, Mar. 31, 1914; 1,091,732, Mar. 31?, 1914; 1,098,728,

June 2,1914; 1,098,776, June 2, 19-14.; 1,098,-

1,108,330, Aug. 25, 1914; 1,108,331, Aug. 25

777, June 2,1914; 1,108,329, 'Aug. 25, 1914;

1914; 1,108,332, Aug. 25, 1924; 1,119,592,

Dec. 1, 1914.

. In the case of those materials from glycerol and phthalic acid (an anhydride-forming aromatic dibasic acid) alone this combination has been observed to pass through three stages, a first solid stage (the A-stage), a second solid stage (the B-stage) and .third solid stage (the C-stage), The ultiiaate industrial utility of these resinous products .lies in their use in molding and like compositions. For this the above-described B-stage product of the glycerol-aromatic dibasic acid group has never been described or indicated, although such B-stage products have themselves been known for, many years.

Now, it remained for us to'disc'over that these relatively useless B-stag'eproducts can be converted into very useful and highly d es-j sirable products which are then among the very best insulating materials available to the industries.

In addition we have also discovered that usetulC-stage products can be made from the less useful B-stage products resulting from glycerol and a polynuclear aromatic acid, such as diphenic acid, 1.8 naphthalic acid, .benzoyl-benzoic acid, methyl-benzoylbenzoic acid .and chlor-benzoyl-benzoic'acid,

and an aliphatic dibasic acid. Furthermore,

we have also discovered that a tribasic aliphaticacld, such as citric acid and malo .malic acid, can be employed in place of dibasic aliphatic acids inproducing. useful 0- stage products either alone or in mixture w1th the above-named aromatic acids.

In converting these relatively useless B stage products into our new products, we have thereby caused the latter to retain substantially all of the elasticity and flexibility of the B-stage products from which they are respectively made, while we have at thev same time increased the electrical insulating properties of our new products beyond that .of the corresponding B-stage products. These changes, alone or together, would not add to the utility of the B-stage products in any substantial manner. However, our new products do difier from the B-stage products from which they are respectively derived in one most essential particular and the one which enables our new products to be used under circumstances where the corresponding B-stage roducts cannot be employed at all. These composed or so altered by cannot be employed in-p contact is unavoidable such as in submarine water that they stage products are all deaces where water cables or in exterior and openly exposed positions where they are subject to action of acts under these conditions become soft or spongy or porous, lose in elasticlty and flexidew, rain, snow or frost. The B-stage prodbility and also'lose in cohesiveness, resist- I ance-to shocks-friction and to the passage of electric current, while our new products suffer no material change in any orall of these respects through such water contact, while at the same time they can equally well be employed in any and all other uses to which the B-stage products have been successfully ut. p To effect this change of the old. B-stage products above'referre'd to into our new products, we apply prolonged and high heating to these B-stage products until the change to our new products has been satisfactorily effected. In general, this is the 4 same means employed to convert the B-sta products of the glycerol-phthalic acid resin 6 into the corresponding C-stage product. 9

(See) U. S, Patent 1,108,330, August 25, 1914 I11 general, these 'A-stage products we operate with are hard without being sticky and are fusible; upon proper heating these A- stage products all become infusible and reach the B-stage which B-stage products, when submerged in boiling distilled water, becomes coated with a bloom, always in less than two minutes; these-B-stage products, when further properly heated, remain infusible but lose the above described sensitiveness to water when the C-stage has been reached. These properties are so sharp and so characteristic that an operator can, with certainty, determine when he has arrived at each of these three stages, when making these materials in bulk.

We have employed the following polybasic aliphatic acids; among the dibasic acids we have employed and found useful are the following: fumaric acid; maleie acid'amalic acid; succinic acid and tartaric acid; among the tribasic acids we have employed and found useful are citric acid and malo malic acid. Malic-acid is represented by the following formula, to wit:

OH(OH)'OOOH oH oooH We have employed the following mixtures of the foregoing as well as others not mentioned below. The figures in the table repre-. sent the molecular proportions of each acid used.

Snccjnic acid Fulnaric Maleie aeid- Tnrtm-ic acid acid Accordingly, the expressionphthalic acid as used above and hereinafter, when not otherwise specified or indicated, is intended to designate both the acid as such or its equivalent anhydride. We-have employed phthalic acid, an aromatic dibasic acid,'both as such and as its anhydride, in mixture with 'tained by taking out the foregoing dibasicaliphatic acids, as-

shown, for example, in the following table:

Suceinic Phthalic acid Fuxnaric acid \Ve have employed glycerol, glycol, di-

hydride with benzol, toluol and chlor-benzol respectively in the presence of aluminum chloride, in the lnanner well known to chemists, and have obtained satisfactory resins.

We have also made resins with each of these aromatic acids mixed with one or more of the previously mentioned polybasic aliphatic acids and have obtained satisfactory and useful results.

' PRODUCING THESE PnonUc'rs IN BULK. Example I-Pwrt A.

A-szage resin from. glycerol and maleiic a-cz'alr Heat together quantities of glycerol and-maleic acid in the proportion of one.

molecular weight ofglycerol to one molecular weight of acid. The acid dissolves forming a homogeneous mass. As the heating is continued, the melting point gradually rises, and the material, which at first is quite stickyand Viscous, eventually loses its stickiness and becomes more-solid. when cold. The completion of the first reaction can be ascera small sample, and allowing it to cool. If the cooled product is viscous or tenacious but not sticky, the reaction has gone far enough. At this stage polyhydric alcoholic the product is sp'luble in' acetone, making a clear solution useful as a varnish. time the melting pomt is usually ov r 90 C. and may be as high as 120 C. (melting points taken by, the method described" on page 821, vol. 10, Journal of Industrial and EngineeringChemistry). The time required to reach this point may vary according to the temperature .at which the heating is con- .By this i minutes in boiling distilled water does not show a bloom on its surface. The time ref quired to accomplish this change de ride on ducted, the bulk of the material employed,

and the rate of stirring. It is seldom ad vantag'eous to let this temperature exceed 200 next step in the-reaction. On the other ,hand, it is desirable to keep the temperature as high as possible (i. e., as near 200? C. as possible) because the reaction otherwise proceeds slowly. For example, a batch of two pounds may be converted at 170 C. in approximately 20 hours. If the material is cooled before the next stage of the reaction sets in, the product obtained is fusible and soluble in cold acetone. This resin is also soluble at room temperature in ethyl alcohol and ethyl acetate although not so much as in acetone. It dissolves slightly in benzene. Cold water acts on it rapidly, causing it to become discolored and soft.

Example I-Pa rt B.

B-stage' resin from glycerol and malez'c acd.-Heat the product of Example 1- Part A until a specimen on suitable test shows that it is no longer fusible, that it is insoluble irr cold acetone, and also that it is eftectedwhen submerged in boiling dis tilled water for two minutes. The temperature of heating may be as high as in Part A, but in that case the reaction becomes violent, frothiiig and evolution of heat take place, and the material becomes filled with bubbles.

V This frothy product may be rendered homoeneous b comminuting it and then mold-' mg 'it' un er heat and pressure. 'A bubble free product may be obtained directly, howi ever, by heating-at a temperature'properly terials for a considerable time, the finely powderedresin swells and forms a sort of I i acids-Heaths product rom' Example I-- at or near the melting point of the 'A-stage resin;-the maximum temperature should not be above about 135 C. and the temperature may be as low as 90 C. or lower. By whichever method it is obtained, the resin is infusible and has no true melting point,.although it softens sufliciently to be-molded' under heat and pressure. It is insoluble in ace tone, ethyl alcohol, and ethyl acetate, but on standing in contact with any of these niajelly-like mass. For example, a batch of two pounds may be converted at 135 C. in about ten hours from the-A-stage resinto the B-stage -resin.' 6'. O-stage resinfromjg carol andwmleic Part-B to a temperature of 170-200 C. until a test specimen when submerged for two the temperature used and on the bu of the material heated. with a large bulk of resin it is important at firstnot to raise the temas it is then difiicult to control the transformer oil.

l perature too rapidly, for the resin is not a conductor of heat and considerable time is required to equalize the temperature.

The final temperature may be as high as I 250C. when time is important. .For example, a batch of two pounds may be converted at 170 C. in approximately 30 hours.

In place of maleic acid of Example I, we have used the following-malic acid; fumaric acid; succinic acid, and malo malic acid, and with satisfactory results. Moreover, we have used various mixtures of these acids as well as mixtures containing one or moae of these acids together with phthalic aci These final C-stage products are insoluble operations. They are resistant to heat, al-

though they burn when put in a flame. The insulating value of the C-stage resins is considerably higher than that of the respective B-stage resins from which they are derived. Thenew products, moreover, are resistant to cold and to boiling water. Prolonged contact with cold water does not diminish thev lustre or polish of thesurface, and the water remains neutral to litmus.

They are substantially unattacked at room.

temperature by 20% solutions of sulphuric, hydrochloric, nitric, or acetic acid, but they will not withstand concentrated sulphuric acid or hot concentrated nitric acid. They are not materially attacked withirf one hour by a'20% solution of caustic soda at the ordinary room temperature. boiling in contact with this solution, the resins are decomposed, forming alcohols and sodium salts corresponding or related to the.

alcohols and acids used in their manufac-, ture. i

While these new C-resins' can be used .as such for certain purposes, the best, most convenientandpractical method of manufacture isto apply the finalheat treatment at the place or in the form-oftheir ultimate use. This is particularly the case when fillers are to be incorporated with the resin, as

' it is often more convenient to compound theresin and fillers before thef-final heat treat- 'ment isvapplied; I v f For example, thefinished- C-resin ma be finely ground, mixed with nix-suitable if desired, and molded b the applicat on of heat and pressure in the way usual in such However, on

operations. We have found that we can employ not only the more expensive kinds of fillers, such as fibrous asbestos, cotton,

Example [I p Producing a molded article containing 0- resin from the B-resin.T he B-resin and the filler, or fillers, are ground separately and then thoroughly mixed in the way usual in such operations. All the materials must be -finely ground to produce an'even mixture.

The relative proportions of resin and filler will naturally vary according to the partic: ular-purpose for which the molding composition is intended. The mixture thus produced may be molded under heat and pressure, and the final heat treatment, as in Example IPart C, then applied with the molded object still in the mold, or the heat treatment may be applied first and the composition then molded. It is not always nec-- essary to carry out the entire heat treatment 1n the mold, and the molded object maybe removed as soonas it has attained sufficient rigidity to maintain its proper form'under further heating, thus releasing the mold for further use and consequently cheapening the process. I

Example 111.

' Producing a molded article comtai ning .O-resin from the B-resin.-The B-resin is finely ground-and allowed to stand in contact with acetonefora considerable time. The-powdered resin swells and forms a jellylike mass, which is also a suitable form for compounding-with a large proportion of filler by kneading or passing between rolls in the usual way in such operations. The composition thus produced is heated to drive i oil" any excess of solvent and may then be handled as in the preceding example. Alternatively, the composltlon' may be molded before driving oil the solvent, and the sol- 'ventmay then be driven ofl while the object is still in the mold. 4

Example I V. Producing a molded article containing U-resin from the A-resin.--The A-resin is melted and the finely ground filler added thereto. I The mixture isthoroughly stirred 'and heated until it becomes infusible and has thus reached the B-stage. Heating is f continued beyond this point as in Example --'I,,to the C-stage; the composition is then ground andmolded under heat and pressure soda in water untilall or memos plete the heat treatment entirely before the molding operation is carried out, but the heat-treatment may be interrupted at such a stage that the heat applied in the subsequent molding operation suflices to produce a finished C-stage product.

Our new produ s an be distinguished with certainty from all other heretoilbre known products by making the following two tests I. Place a specimen thereof in boiling distilled water; if its surface remains bright and does not become dull in two minutes, it is water-resistant in the sense we have herein used and will hereafter use that expression. 11. Boil a specimen, say 1 gram, with ten times its bulk of a 20% solution of caustic into solution; filter; cool; acidify'with hy-' drochloric acid. From the product of these operations tartaric acid, fumaric acid or succinicacid can all be recovered as such by means usual with chemists for such purposes, from such resins in whose production they have-been employed. Maleic acidand .malic acid may be recovered partly as such,

but these acids, when used formaking our new products, may also be recovered entirely or in part only asl fumaric acid, which is a well known transformation product of each of those two acids.

nearly-all has gone We have described generally a continuous and continuing procedure from a mixture of glycerol and an acid or acids'to the final water-resistant C-stage resin, but we wish it to be understood that either such a continuous or such discontinuous process can be used with equal satisfaction. That is, we may proceed from the glycerol and acids to either the A-stage or the B-stage and subsequently to the C-stage, or we may begin with the A-stage or B-stage resin and proceed to C-stage resin therefrom.

These resins all belong to the general class of plastics, and while we have specifically mentioned that they can be used to produce a molded article, it must be obvious to all that they are by no means restricted to such enumerated uses but can be used in many other places and in many other operations and for many other purposes where plastic materials can be used. It is also obvious that our invention includes these resins whether produced and-used as such or whether produced in admixture or association with other ingredients, or used. in ad mixture or association with othermgredients, and that the term resin as used in ingredients with said resins.

' We claim 1. A water-resistant malic acid-glycerol about 10 hours,.th en between 17 and 250 resin.

2. The process of making a resin, which comprises heating malic acid and a polyhydric'alcohol for about 20 hours between approximately 17 0 and 200 (3., then below 135 C. for about hours, then between 170 and 250 C. unt1l a water-resistant resin results. I I

3. The process of makinga resin, which comprises heating malic acid and glycerol for about hours between approximately 170 and 200 C., then below "135 C.for

about 10 hours, then between 170 and 250 4. The; process of making. a resin, whic comprises heating malic acid, an anhydride then below 135 forming aromatic diabasic carboxylic acid and glycerol for proximately 170 and 200 C., then below 135 C. for about 10 hours, then between 170 and 250 until a water resistant resin results.

-5. -The process of making a-resin, which comprises. eating malic acid, an anhydride forming aromatic -dibasic. carboxylic acid anda polyhydric alcohol for about 20 hours between approximately 170 and 200 C.,-

C. for about 10 hours, then and h 11. The

about 20 hours between ap-' between 170 and 250 C. until 'a water-resistant resin results.

6. The process of making a resin, which comprises heating-malic acid, phthalic acid glycerol for about 20 hours between 170 and 200 (1, then below 135 C. for

obtained from malic acid and a polyhydric alcohol.

10. A water-resistant resin such as can be obtained from malic acid, phthalic acid and glycerol.

recess of makin comprises eating malic aci and a polyhydric alcohol for a out 20-hours between approximately 170 and 200 (1., then below 135 (3., for about 10 hours, then between 170 and 250 (3,. until a water-resistant resin results.

12. A, water-resistant malicacid-polyhydric alcohol resin.

In testimonywhereof we aflix our signatures.

a resin, which acid-phthalic CHARLES R. Downs. Lou s WEISBERG.

hthalic acid i 

